Calf muscle perfusion at peak exercise in peripheral arterial disease: Measurement by first-pass contrast-enhanced magnetic resonance imaging
✍ Scribed by David C. Isbell; Frederick H. Epstein; Xiaodong Zhong; Joseph M. DiMaria; Stuart S. Berr; Craig H. Meyer; Walter J. Rogers; Nancy L. Harthun; Klaus D. Hagspiel; Arthur Weltman; Christopher M. Kramer
- Publisher
- John Wiley and Sons
- Year
- 2007
- Tongue
- English
- Weight
- 440 KB
- Volume
- 25
- Category
- Article
- ISSN
- 1053-1807
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✦ Synopsis
Abstract
Purpose
To develop a contrast‐enhanced magnetic resonance (MR) technique to measure skeletal muscle perfusion in peripheral arterial disease (PAD).
Materials and Methods
A total of 11 patients (age = 61 ± 11 years) with mild to moderate symptomatic PAD (ankle‐brachial index [ABI] = 0.75 ± 0.08) and 22 normals were studied using an MR‐compatible ergometer. PAD and normal~max~ (Nl~max~; N = 11) exercised to exhaustion. Nl~low~ (N = 11) exercised to the same workload achieved by PAD. At peak exercise, 0.1 mm/kg of gadolinium diethylenetriamine pentaacetic acid (Gd‐DTPA) was infused at 3–4 cm^3^/second followed by a saline flush at the same rate. A dual‐contrast gradient echo (GRE) sequence enabled simultaneous acquisition of muscle perfusion and arterial input function (AIF). The perfusion index (PI) was defined as the slope of the time‐intensity curve (TIC) in muscle divided by the arterial TIC slope.
Results
Median workload was 120 Joules in PAD, 210 Joules in Nl~low~, and 698 Joules in Nl~max~ (P < 0.001 vs. Nl~low~ and PAD). Median PI was 0.29 in PAD (25th and 75th percentiles [%] = 0.20, 0.40), 0.48 in Nl~low~ (25th, 75th % = 0.36, 0.62; P < 0.02 vs. PAD), and 0.69 in Nl~max~ (25th, 75th % = 0.5, 0.77; P < 0.001 vs. PAD). Area under the ROCcurve for PI differentiating patients from Nl~max~ was 0.95 (95% confidence interval [CI] = 0.77–0.99).
Conclusion
Peak‐exercise measurement of lower limb perfusion with dual‐contrast, first‐pass MR distinguishes PAD from normals. This method may be useful in the study of novel therapies for PAD. J. Magn. Reson. Imaging 2007. © 2007 Wiley‐Liss, Inc.